Power cables, which may be used for electric submersible pumps (ESP) in oil wells, are typically constructed with a copper conductor, an insulator that surrounds the copper conductor, and a lead sheath that surrounds the insulator. Lead-sheathed power cables are known and disclosed in, for example, U.S. Pat. No. 4,780,574 to Neuroth and U.S. Pat. No. 5,760,334 to Ziemek, each of which are incorporated by reference herein in their entirety.
The lead material of the lead sheath protects the insulator of the power cable from damage resulting from the deleterious gases of the harsh oil well environment. The lead material of the lead sheath may also protect rubber sealing elements that are used to terminate these power cables. The rubber sealing elements are particularly vulnerable to explosive decompression and other types of damage caused by the gases.
Lead is commonly used because it is substantially impermeable to gas and moisture, inexpensive, flexible, ductile and easily removable. However, many of these qualities also make the lead sheath susceptible to damage upon changes in pressure and temperature if attempts are made to rigidly attach the lead sheath to a metal shell of a connector.
The invention described herein maintains the gas permeation protection provided by the lead material while offering a robust solution that can better withstand mechanical handling as well as changes in pressure and temperature.